An application of a lithium-ion secondary battery rapidly broadens as a battery for a hybrid car. Further, it is prospective that a production volume of a large-size lithium-ion secondary battery would increase at a great rate because a capacity of its unit becomes large. Manganese, cobalt, nickel and lithium are used as positive electrode materials of the lithium-ion secondary battery. However, it is hard to say that their recovering method is established at present. Among them, though lithium is an essential element of the current lithium-ion secondary battery, its recover is hardly conducted at all. It is obvious that an amount of emergence of waste lithium-ion battery increases along with the popularization of a battery car and the like, and the recover of lithium would be important.
There is a method as disclosed in Japanese Patent Application Laid-open Publication No. 06-88277 (Patent document 1) as one of the recovering method of lithium. It is suitable for recovering lithium from diluted lithium solution. However, it cannot be used for a high concentration solution provided in separating each element from a lithium-ion waste battery.
There is a method as disclosed in Japanese Patent Application Laid-open Publication No. 2006-57142 (Patent document 2). Lithium is extracted by an acid system solvent extraction agent from a solution containing a low concentration lithium ion, then a reverse extraction is conducted, and then lithium is recovered from the provided solution in a form of carbonate in the method. However, an extraction rate of lithium in the solvent extraction is low, namely 50%, and a recovering rate of lithium of the total is low.
A method as disclosed in Japanese Patent Application Laid-open Publication No. 2005-26089 (Patent document 3) is a method for recovering lithium from waste lithium-ion battery in a form of carbonate. However, in the method, an increase of an equipment cost and a manipulatory vexatiousness cannot be evaded because lithium containing solution and CO2 gas are contacted in a pressure container when carbonate is produced.    (Patent documents 1) Japanese Patent Application Laid-open Publication No. 06-88277 (A method for recovering lithium and electrode used in the method)    (Patent documents 2) Japanese Patent Application Laid-open Publication No. 2006-57142 (A method for recovering lithium)    (Patent documents 3) Japanese Patent Application Laid-open Publication No. 2005-26089 (Lithium battery, a method for preparation and treatment thereof)